Enumerated (enum) types are data types that comprise a static,
ordered set of values. They are equivalent to the enum types supported in a number of programming
languages. An example of an enum type might be the days of the
week, or a set of status values for a piece of data.

The ordering of the values in an enum type is the order in
which the values were listed when the type was created. All
standard comparison operators and related aggregate functions
are supported for enums. For example: